There currently exists wire cutting systems for EOD use which employ detonators and squibs. These systems produce unwanted blast and fragmentation. In addition, they are classed as explosives, can initiate the explosives in the suspect device while attempting disarmament and engage a plethora of shipping and handling concerns.
Examples of systems performing mechanical movement explosively include Yunan, U.S. Pat. No. 4,722,279 which discloses a nonelectric detonator device having a tubular shell that is closed at the bottom end and containing a base charge, a primary charge, a rupturable membrane, a holder for low energy detonating cord whereby on detonation of the detonating cord the membrane is initiated which in turn initiates the detonating explosive.
Another example is Lake, U.S. Pat. No. 4,062,112 issued Dec. 13, 1977 which teaches an explosive wire cutter using a barrel and a piston. This cutter is adaptable to various types of charge, all of which are explosive.
Patrichi, U.S. Pat. No. 3,991,649 discloses a pyrotechnic wire cutter using an explosive charge to sever a wire or wires.
Other examples of explosive devices, including wire cutters, are now in the art but suffer from a lack of precision timing as well as the concerns attendant with explosive devices.
Efforts in the field to reduce the effects of explosive devices are known to employ shock tube. These devices use the nonelectric shock tube to then ignite an initiation material which in turn ignites propellants or other explosive materials to perform work functions. Examples of these devices include Burkdoll et al., U.S. Pat. No. 4,664,033, which uses shock tube to pyrotechnically ignite a first fire material which in turn ignites a propellant which moves a ball bearing against a seat to close a valve.
Florin, U.S. Pat. No. 4,809,610, also uses shock tube in a device to time multiple detonator delays. This system also uses the shock tube to ignite a secondary charge, thus continuing the concerns surrounding the use of explosive materials.
All known uses of shock tube utilize the ignition property of the transfer tube to ignite secondary mixes of either pyrotechniques or explosive material. These, like other pyrotechnic or explosive pin-pullers or wire cutters, engender an imprecision in timing, as thermal thresholds vary. Any multiple wire cutting system using these techniques would have simultaniety variances of milliseconds or greater. Increasingly EOD applications require multiple wire cutting, with an increased degree of severance simultaniety not possible with explosive or pyrotechnic devices.